In orthopedic and dental surgical applications there is a great need for biocompatible and bioresorbable implant material which can be conveniently and effectively used as a bone substitute. This includes bone lost due to periodontal disease, ridge augmentation, sinus elevation, bone defects or cavities due to trauma, disease or surgery and spinal fusions. Following implantation the bone substitute is ideally resorbed in a time frame which is consistent with its replacement by new vital bone.
The bone graft material of preferred choice is autograft, i.e. the patients own bone, since this is totally biocompatible, is not subject to an immune response or disease transmission and has good osteogenic capacity. However, its source is limited, it requires a second surgical procedure for harvest and there are often donor site morbidity problems.
Allograft bone is usually considered an acceptable alternative since it is more readily available and has a reasonable level of efficacy. However, it has the potential for disease transmission and since it is ‘foreign’ tissue there is the potential for immunological reactions. In addition, it is a material variable in its properties, due to donor source (often elderly people with osteoporotic bones) and processing variability. This makes prediction of clinical outcome difficult when allograft is used. Delayed healing is a frequent complication.